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- Whether you're setting up accounts for existing users on a new server or providing accounts for a crop of new staff members on your primary server, it's nice to be able to do the job quickly and accurately. The newusers command in Linux is designed to make this process as smooth as possible, but it may not do everything you expect -- especially if your data file is, uh, sloppy. Let's take a look at what it does and where it might fall short of expectations.
48 weeks 20 hours ago
- Bash has quietly made scripting on Unix systems a lot easier with its own regular expressions. If you're still leaning on grep and sed commands to get your scripts to do what you need from them, maybe it's time to look into what bash can do on its own.
49 weeks 2 days ago
- Cron is not in charge; you are. All you need to do is tell it what you want done and when you want it done.
50 weeks 2 days ago
- Don't let an ISO 27001 audit ruin your week. Chin up and follow some simple rules to chase away the pain and the worry.
51 weeks 2 days ago
- Sandra Henry-Stocker wrote Unix: Cheat sheets -- everything you wanted to know about everything ... almostA treasure trove of cheat sheets is yours for the clicking. Visit OverAPI.com for help with nearly any language or tool imaginable.
1 year 1 day ago
- A number of people have asked recently what it takes to be a Unix systems administrator, what “core competencies” are required, and what are the best and worst aspects of the job. Here are some answers that might work once we get beyond “it depends”.
1 year 1 week ago
- Are you someone who never met a Unix command you didn't like? OK, maybe not. But are there commands you just can't imagine living without? Let's look at some that have made a big difference on my busiest days and those that people I've worked with over the years have said are their most important essentials.
1 year 2 weeks ago
- While pipes are one of the things that make Unix such a powerful and versatile operating system, they don't always make sense. Many people still fall into the "useless use of a pipe" habit while still others use pipes in situations in which pipes simply don't function at all. Knowing when to pipe and when not to pipe remains a sign of Unix mastery. If you want to look Unix savvy, use pipes only when they provide a critical service and never when they're superfluous or downright wrong.
1 year 3 weeks ago
- Finding a computer infection that is, above all else, designed to remain hidden is not easy work, but neither is it impossible. With some good insights and tools, you might just get a leg up on how the multi-billion dollar spyware industry is attacking your systems.
1 year 4 weeks ago
- You could have a rootkit infection right now and be totally unaware. One of the key goals of a rootkit is, after all, to go undetected. If the rootkit is hiding files, processes, logins, etc., how would you know? If you can't see it, how would you remove it?
1 year 5 weeks ago
- If you haven't worried about rootkits in a while, what are you waiting for? Rootkits remain one of the stealthiest and most worrisome forms of malware compromising systems today.
1 year 6 weeks ago
- If you've ever wondered how Unix systems identify files, you might be surprised to learn that file names really aren't an important factor. Unix systems reach into files looking for special codes called "magic numbers" to figure out what your files really are. They also examine other file content to pick out additional details.
1 year 7 weeks ago
- Malware represents one of the greatest threats that organizations face today and IT departments are coming to understand that their AV tools can only do so much to protect them. When malware is discovered on their systems, they want to know what it might have done, if the threat is still ongoing, and what they might have lost to the infection. Answers can be very tough to find, but reverse engineering the malware might just be the way to provide them.
1 year 8 weeks ago
- Don't throw up your hands if your boss won't buy you Tripwire and a modern debugger. There are a lot of things that your Unix system -- right out of the box -- can tell you about files and processes.
1 year 9 weeks ago
- The quickest way to determine what and how many processors are installed on a Linux system is to turn to the mighty gateway of kernel data -- the /proc pseudo-filesystem. In it, you'll find a file called /proc/cpuinfo that provides a lot of information in the processors in your system. Read on to see how easily you can get answers to questions and an explanation of what those answers really tell you.
1 year 10 weeks ago
- Hard links are not called "hard" because they're difficult. They're just ... mildly elusive. Read on and find out why one long-time Unix admin thinks hard links are the penguin's meow.
1 year 11 weeks ago
- Planning to spend the next six months fighting with troublesome data that you might have to scrub, decode, reformat, store, classify, annotate, visualize, analyze, explain, report and then start all over again? Maybe you should first get some advice from others who have been there, done that.
1 year 12 weeks ago
- If you're only comfortable with CIDR when the / is followed by a multiple of 8, a quick refresher on how the numbers work might be just what you need for a balmy January afternoon.
1 year 13 weeks ago
- Before the chilly winds of a RIF blow in your direction or a pile of your friends take off for greener pastures, you need to be prepared with an easy way to freeze account and preserve what might be of value in the abandoned home directories. In today's post, we'll look at some commands for inactivating accounts on Unix systems and provide some starter scripts for you to adapt to your environment.
1 year 14 weeks ago
- Sandra Henry-Stocker wrote Python for kids ... and adults intimidated by the very idea of programmingIf you love Unix but fear programming or have a kid who you'd like to convince that programming is fun, here's a book you really should consider.
1 year 15 weeks ago
- Complexity isn't all bad. Sometimes it comes with a tremendous boon to security. Are you ready to cozy up to SELinux? Maybe it's time.
1 year 16 weeks ago
- Hardening tips for Unix systems have been issued for decades, but when's the last time you stopped to review how your servers stack up against the latest advice from the sages? Let's check out some of the recommendations provided for Red Hat Enterprise Linux 5 and see what you might gain or lose by implementing them.
1 year 17 weeks ago
- As we find ourselves hurtling toward 2013, it's a good time to think about all the things that we Unix admins would never do ... and how that keeps us out of trouble.
1 year 18 weeks ago
- Do you get calls at odd hours because some critical service that you support on your Linux server has stopped working? Here's some late night reading that might help you get the rest you deserve.
1 year 19 weeks ago
- Iptables, more properly referred to as "iptables/netfilter" because of the two modules that are involved -- the userspace module "iptables" and the kernel module "netfilter" -- is the firewall that you'll find running by default on most Linux systems today.
1 year 20 weeks ago